1. Field of the Invention
The present invention relates to a portable apparatus for use as an applicator or dispenser of a pasty or similar product by means of a rotary coating pad, this product consisting for example a boot-polish or other similar shoe-shining or treatment products.
2. Description of the Prior Art
In the U.S. Pat. No. 4,016,617 the applicant already disclosed and illustrated a portable apparatus intended for the same use. In this known apparatus the coating pad is carried by a cartridge filled with the treatment product and rotatably driven by an electric motor housed within the case of the apparatus.
The product is forced outwardly by a spring-loaded piston so that it impregnates the porous applicator pad and flows through this pad when the latter is caused to contact a surface to be treated.
However, the presence of a piston constantly urged by a spring located within the cartridge is a source of difficulties when it is desired to refill the cartridge when the latter is empty. In fact, in this case the cartridge must have a filling hole provided with a non-return or safety valve to prevent the subsequent outflow of the cartridge current.
But in this case, it is not possible to fill the cartridge unless the product is driven into it with a force sufficient to open the valve and at the same time cause the piston to recede against the force of its spring. Under these conditions, this refilling operation is difficult to achieve, inasmuch as the product is usually kept in a tube of deformable material to which it is hardly possible to apply a relatively strong pressure.